.. _file_include_predicates.hpp:

File predicates.hpp
===================

|exhale_lsh| :ref:`Parent directory <dir_include>` (``include``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS



Size/align key wrappers, comparison predicates, and operator tag mapping. 



.. contents:: Contents
   :local:
   :backlinks: none

Definition (``include/predicates.hpp``)
---------------------------------------


.. toctree::
   :maxdepth: 1

   program_listing_file_include_predicates.hpp.rst



Detailed Description
--------------------



- ``HasStaticSize`` concept gates types that expose ``static constexpr std::size_t size``.

- ``Size<T>``, ``SizeOf<T>``, ``AlignOf<T>`` present a unified ``::type`` and ``::size``.

- ``cmp``, ``PredBy``, ``op_tag``, and ``ops`` build size-based predicates.

- ``op_type<"...">`` maps a compile-time string token (e.g. ``"<"_ct``) to an operator tag whose ``template pred<L,R>`` can be used in algorithms (e.g. partition/sort).

- Helpers ``Size_t``, ``SizeOf_t``, ``AlignOf_t``, and ``Apply<S,...>`` create keyed typelists.




Example

structA{staticconstexprstd::size_tsize=3;};
structB{staticconstexprstd::size_tsize=5;};

usingLT=:ref:`exhale_typedef_predicates_8hpp_1adc079efedc1088be4f5cf68b7a56d779`<"<"_ct>;//operatortagforless-than
static_assert(LT::templatepred<A,B>::value);//3<5

usingKeys=:ref:`exhale_struct_structctql_1_1detail_1_1HTList`;//HTList<Size<A>,Size<B>>






Includes
--------


- ``concepts`` (:ref:`file_include_concepts.hpp`)

- ``cstddef``

- ``ct_string.inl`` (:ref:`file_include_ct_string.inl`)

- ``functional``

- ``htlist.hpp`` (:ref:`file_include_htlist.hpp`)

- ``match.hpp`` (:ref:`file_include_match.hpp`)



Included By
-----------


- :ref:`file_include_partition.hpp`

- :ref:`file_include_reduce.hpp`

- :ref:`file_include_sorted.hpp`




Namespaces
----------


- :ref:`namespace_ctql`


Classes
-------


- :ref:`exhale_struct_structctql_1_1AlignOf`

- :ref:`exhale_struct_structctql_1_1cmp`

- :ref:`exhale_struct_structctql_1_1op__tag`

- :ref:`exhale_struct_structctql_1_1ops`

- :ref:`exhale_struct_structctql_1_1PredBy`

- :ref:`exhale_struct_structctql_1_1PredBy_1_1t`

- :ref:`exhale_struct_structctql_1_1Size`

- :ref:`exhale_struct_structctql_1_1SizeOf`


Typedefs
--------


- :ref:`exhale_typedef_predicates_8hpp_1a6ef2c8845cf9e10e5c0ddf9f267736d1`

- :ref:`exhale_typedef_predicates_8hpp_1ab69cae58abfbba3a1585fc562678e38f`

- :ref:`exhale_typedef_predicates_8hpp_1adc079efedc1088be4f5cf68b7a56d779`

- :ref:`exhale_typedef_predicates_8hpp_1a7c12ca8e8e8edd3dd1ac24487c929252`

- :ref:`exhale_typedef_predicates_8hpp_1a9b556f1eabfa3c09ed01a7d82bb69fec`